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    <title>Document</title>
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<body>
    <script>
        
        var r = +prompt('圆的半径是多少')
        // 声明半径
        console.log(r);
        // 打印收集半径信息
        var per = 2 * 3.14 * r;
        // 声明周长
        var area = 3.14 * r * r;
        // 声明面积
        var all = `圆的半径是${r},周长为${per.toFixed(2)},面积为${area.toFixed(2)}`;
        // 声明所有信息
        console.log(all);
        // 打印所有信息



    </script>
</body>

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